Further de-linting of zoneinfo module (GH-20499)


* Remove unused imports in zoneinfo

* Remove unused variables in zoneinfo

* Remove else after raise
(cherry picked from commit 364b5ead1584583db91ef7f9d9f87f01bfbb5774)

Co-authored-by: Paul Ganssle <paul@ganssle.io>
4 files changed